StarTalk Radio - Things You Thought You Knew – Quantum Cat

Episode Date: October 7, 2025

What happens when you fall into a black hole? Neil deGrasse Tyson and Chuck Nice give us the step-by-step on spaghettification, explain Schrodinger's cat, and explore quantum tunnelling… Or do they? NOTE: StarTalk+ Patrons can listen to this entire episode commercial-free here: https://startalkmedia.com/show/things-you-thought-you-knew-quantum-cat/Thanks to our Patrons Peter Nguyen, Noah Narh, Oliver Anderson, Oleksandr, TULAKAR JHA, Marziee, Carmen, Erica Trebesch, Joan Cotkin, Steve, Kevin, renee porter, Knatrueall Phliights, Jacque Walker, ThatOofcaGuy, Ian Ulsh, Robert Vest, Oslo Johnson, Colin T, Patricia Brennan, Mac Lamken, Josh, Derek Holiday, ShieldsGaming18, Adam Gotch, Mike Starnes, Ryan, AnJ, William Rosati, Chris Ose, Becker the Brewer, Jennings.Bass, LAZU, Alissa Wilson, Logical Haus, Dave Blair, Brad, Kaleo Hubert, soogun shongwe, Caleb Pelletier, Toby Murray, McGrumps the Curmudgeon, Joshua, Knutte Söderberg, Albert Dávid, Jim Prescott, John Wooters, Chris Raines, neoghaleon, Roy Roddey, PJ, TC, Micheal Bartmess, Arwa, Hasemano, Brian Thompson, Stetson, Goerc Goerc, Dennis Shields, Spike, Ian Hebert, Kasheia Williams, Tess, Aren Moy, Robert, LittleBoBliue, Paul, Rick Hanes, Donivan Porterfield, Tony Smith, Penny B, Brett R, Nicholas Falvey, and Stymie Sulik for supporting us this week. Subscribe to SiriusXM Podcasts+ to listen to new episodes of StarTalk Radio ad-free and a whole week early.Start a free trial now on Apple Podcasts or by visiting siriusxm.com/podcastsplus. Hosted by Simplecast, an AdsWizz company. See pcm.adswizz.com for information about our collection and use of personal data for advertising.

Coming up on StarTalk, it's another Things You Thought You knew episode. This time, we bring to you a few fan favorites, death by Black Hole, Schrodinger's cat, and quantum tunneling. Don't want to miss it. Welcome to StarTalk. Your place in the universe where science and pop culture collide. StarTalk begins right now. I want to describe what it's like to die as you fall into a black hole. Now, are we recounting a personal experience here?

Perhaps that could be the reason for the delay in discussing this. Are you sure you're ready for this after this harrowing experience? One of the highest compliments I ever got was I was giving a tour of the newly built Hayden Planetarium, renovated to Seinfeld, okay, who lived across the street. So he was a neighbor. What's the deal with the lights? Well, right. So I described the big bank to him in the first few moments and in exquisite detail. And he says, it sounds like you were there. I thought, man, that's a high compliment. I'd never forget that. That's pretty funny. So I'm about to describe death by Blackholt and no, I will alert you in advance. I was not. I was not.

not there. Okay. But we know the physics of it. And that's just as good. Okay. All right. So a black hole. So you're standing here on Earth. All right. I am, by the way, sitting. You're sitting on Earth. And your feet are closer to the center of the earth than the top of your head is. Okay. Do we agree? I will agree. I'm not that short. So yeah. You have to be really short for that not to be true. You've got to be Kind of like a Mr. Potato Head. Just have your feet right at the bottom. Right up under your neck. I guess Mr. Potato Head didn't have a torso.

No. Oh, my gosh. That's right. Oh, that is sad. Yeah, it is. How come I never noticed that? That's right. Mr. Potato Head was all head.

It was all head and feet. Arms and feet. That was it. Arms coming out of the side of his head. That's right. Arms, right. All right. So, you can calculate the strength of Earth's gravity at your feet

and the strength of Earth's gravity at the top of your head. And you'll get a different number. Wow. Because your feet are closer to the center of the Earth. Okay. And the closer you are to an object with gravity, the higher is the gravitational force operating on you. Okay.

So if I do that for you, you're five, nine, something like that, how tall of you? And so, you're 5'10? I want that extra inch. You're a big guy, so you don't care. You're like 6'3, so you don't give a damn. No, I'm 6'2. See, that's what I'm saying, you know.

I gave you an inch. I was 6'2 in high school. I probably, you know, got the old man shrinkage from that. So, all right, so I can write down the difference between those two forces. And it's not going to be very much. So you don't think about it. you don't care about it. It's not much because your height is small compared with the radius of the earth.

Correct. Radies here, it's 4,000 miles, and here you are, you know, just under six feet. So that's, so we don't think about this difference in the gravitational force. We don't have occasion to think about it. But that difference in force has a word. It's called the tidal force. Okay. Okay. Now, the tidal force of the moon operating on the earth, the side of the earth facing the moon feels a stronger gravitational force of the moon than the side of the earth that's on the other side of the earth that's farther away from the moon. You can calculate this, okay? And so the entire earth is stretched in the direction of the moon.

because of this tidal force. Okay. The solid earth is stretched, but that's less noticeable because we're walking around on the solid earth. But what's most noticeable is the oceans are stretched.

And it's called a tidal bulge. All right? And so wherever you're going to find the moon, you're going to find a tidal bulge elongated pointing to the moon. It actually doesn't point, it points ahead of the moon because we're dragging it in our

as Earth rotates, but that's a whole other explainer that we'll get into. For now, just consider it, we're aligned with the moon, okay? So now watch. That's because Earth is big compared to the distance between the moon and the Earth. Okay? So that's why. Earth is bigger compared to that distance

that you are compared to Earth's radius. Right. So now watch what happens. Let's turn Earth into a black hole. Let's just do that. Okay. You know how you do that? You just shrink it. Okay.

Right. Yes. As you shrink it, the gravity on the surface goes up. Why? You're getting closer to the center of the Earth. And it still has all the mass in this model that I'm describing. Okay? Two things tell you how much you weigh.

How far away you are and how much mass is tugging on you. Right. As that happens, your size, which is still 5 feet 10, relative to the size that the earth is becoming is actually more and more significant. Right. Because the earth is no longer 4,000 miles in radius. Correct.

That radius is shrinking and shrinking and shrinking. So it's becoming much closer to my size as it shrinks. Correct. Correct. And when you do the math, the difference in the force between your feet and the top of the head gets greater and greater and greater. Oh. Okay.

So now, let's fall into a black hole and describe what happens. Okay. So here you are falling into a black, towards a black hole. There's no air, so no one's hearing you. Damn it. Okay.

You're just catching flies with your open mouth. there, that's all. All right. So, meteor particles. So you're falling feet first. Let's give you a feet first dive. And the tidal force is slowly getting greater and greater. And initially, it feels kind of good.

Who doesn't love a good stretch? Oh, right? Best spa ever. I know. And then you realize, wait a minute, that stretch is not only not abating, it's getting worse. Uh-oh. We're getting medieval. Yeah, exactly.

We get medieval. This ain't cool. Don't make me get medieval on your ass. I had not thought about how medieval this is. Because you look at the machines they had. It's like, what were they thinking? Let me tell you. Somebody was staying up at night.

Thinking this stuff up. To think of ways to torture and kill people. That is effed up. Yeah. They excelled beyond, you know, imagination. I heard there's another one where they disembowel you, and so that hurts enough. And then they take your intestines out and put it on the fire so that you're not only in pain from being cut open, your organs are in pain after they've removed it because it's still a, you know, your intestines are all stringy, right? So they're still connected to you.

And so, and then you know what being drawn and quartered is? You know what that is? Is that the one where they put you on the horse, the four horses? Yeah, four horses, right. So a horse to each limb, and then they'll score you, right? They'll just so that you cut more easily. Oh, man. We must perforate him now.

Wait for the perforation. So you do that, and when the four horses run away, you were in four different pieces. That is disgusting. No matter what, you are in four different pieces by the time that's done. Well, really, five, because there's a torso laying on the ground. No, no, no, no. No, that's not how it works. No, I thought you, I thought you, so each limb.

Okay. So if, if three limbs are pulled off, the fourth limb is still attached to the rest of your body. No, I thought it was four, like four horses, one for each limb. I know. What I'm saying is, you. your body doesn't rip apart simultaneously, okay? Oh, God. Okay, so one horse rips off one arm.

Oh, no. One other leg, and then another leg, and one arm has slightly more muscle tissue there, holds on to the rest of the torso. I did not know this is how this thing worked. This is, I mean, you just made it ten times worse. I'm saying that what you described, the limbs would have to be equally attached with a forced, force tissue. Exactly. Equally, and simultaneously pulled in exactly the right angles for them to pull off all at

the same instant. And this is not how that works. That's my point. You ruined my fantasy is what I'm trying to die. That you just dropped down in the middle as your four limbs. I just drop in the middle and I'm sitting there like an op long, you know. Then you're not being courted. You're being dismembered.

That's different. You're right. Okay. So this is all a nice preamble for what's about to happen to you. Uh-oh. Okay. So your feet first, falling towards the black hole.

Okay. The stretch feels good, but then it becomes unrelenting. Because your height is now a bigger and bigger fraction of the distance you are to the center of the black hole. All right. So now, you start sliding it and what happens? Oh, my gosh. The tidal force exceed, there will be a point where the title force exceeds the molecular

forces that keep your body attached as one piece. Oh, no, my molecular bond. You're a molecular bond. So you will snap into two parts. That's nasty. And since all the forces are operating uniformly across your body, it's not like a horse yanking on one thing or another. I did a calculation.

I probably have to speak with some physiologist about this, but I think you'll initially snap at your lower spine. Okay? So those are the two bits. Now, those two. two parts of you, continue to feel the tidal force. Okay. So they stretch.

Okay? And so your bottom half snaps into two pieces. Oh, right. Your upper torso snaps into two pieces. And as best as I can judge, that would be at the base of your neck. Okay. Oh. Now, your brain is still working.

You can, in principle, see this. Okay. This happens pretty fast. And by the way, they did these experiments, from what I've read in the French Revolution with the guillotine, right? If you're going to be a guillotine, you might as well help out science, right? So with your head on the ground, before your brain really knows that it can't get oxygen from blood, do your eyes still work? Okay? And so I think they did experiments where they hold up one finger, two finger, and you blink if you saw two fingers or one.

finger just for that leg because your eyes go straight to your brain they don't need your torso for none of that okay so people were messed up in the past okay all right so now you're in four pieces and they continue to feel the title force and then you go from two to four to eight to 16 to 32 to 64 and this continues until you are a stream of atoms, like a train of atoms pouring down to the singularity. And that's not the worst of it. Go ahead. Okay.

The fabric of space and time funnels, funnels, and gets narrower and narrower because it ends up at a singularity. Oh, no. So whatever horizontal volume you. occupied, you become extruded through the fabric of space like toothpaste through a tube. This form of death has a name, and it's called spaghettification. Okay. Well, I mean, I can't believe something that horrific could have such a delicious name. How did this happen?

So I, many years ago, wrote a book called Death by Black Hole. And I thought the book would do well, and the publisher looked kind of askance at me. Like, no, we don't think this is going to do well. I said, dude, look at the title. Come on now. And so they didn't print enough copies when it was first released. And it sold out in a day. Wow.

And then this is before we had, like, Amazon and everything. So when you sell off the shelves, there's nothing. there to buy. But in that week, it hit the bestseller list, but it became a minimum bestseller, right? It hit number 15 for one week. That's a minimum bestseller. But it would have stayed there if there were more books available. More copies. Yeah, so I lorded that over the publisher ever since. But anyhow, Death by Black Hole, and I described this, but also, I want to share with you a poem that I composed about Death by Black Hole. May I? A place still. I'm not a poet, so dare I call it a poem.

I'll call it a rhyme. Okay. All righty. Here it is. Okay. In your feet first dive to this cosmic abyss, you will not survive because you will not miss. The tidal forces of gravity will create quite a calamity when you're stretched head to toe. Are you sure you want to go?

Your body's atoms, you'll see them, will enter one by one. The singularity will eat him, and you won't be having fun. That, I have to say, is the scariest Dr. Seuss book I have never heard. Good night, Timmy. Behave tomorrow. Hello, I'm thinking Broke Allen, and I support StarTalk on Patreon. This is StarTalk with Nailed Grass Tyson. This is StarTalk with Nailed Grass Tyson. This is something you hear.

all the time, especially in jokes, believe it or not. Really? Yeah, Schrodinger's cat. Wait, but you have a quantum division of the joke department? Well, I don't think that the comedians know what Schrodinger's cat is, but it's such a, it's such a ubiquitous reference. Yeah. That they make reference to it a lot of times. It's intercultural.

It's entered pop culture. It has interculture. I don't know why they don't call it Schrodinger's dog. Okay. All right. So, all right. So it dates back to Irwin Schrodinger, who, Irwin, yes. And he was a physicist. Right. They're all won Nobel Prize as all these people who contributed to our understanding of the quantum. Right. And quantum mechanics is what it's officially called. But I like just calling it quantum physics, because it's an entire branch of physics that deals with the small things in the universe. All that is small. Do you sweat the small stuff?

Yes, you do. I see. Precisely. Precisely. And the Schrodinger's cat relates a little bit to what people have called the observer effect. Uh-huh. Okay? If you observe something, you change it.

So I can respond to both of those in the same pop, if you allow me. Okay. So let's do the observer effect for the moment. So it's unfortunate that somebody called it the observer effect, because then New Age, folk and other people who are basically scientifically illiterate were thinking it's your consciousness that affects what you're observing and oh my gosh there's a consciousness field and they go running off in a you know off the cliff see what you don't understand is that like particles are totally alive okay and the reason why there is a collective consciousness in the universe is because like

all of these particles that are spinning what they're actually doing is conducting thought and consciousness? They're thinking. They're thinking, man. Rocks think, trees think more than rocks. So let me cut through all of that and simply say

that you're sitting there and I can see you because in fact you're illuminated by if not sunlight through an open window, an uncurtained window but artificial light within the room. That light hits your face, bounces off your face, goes through, the computing system and I see you, okay?

That light carries energy. Every photon of light that strikes your face carries energy. And then they, most of them reflect. Others get absorbed. Actually, it depends on how dark your skin is. Skin is very dark. It'll absorb most of them. That's because, you know, photons, they want to be a part of this baby.

Let me get some. That goes. Let me get some. I see where we're landing. Oh, we got some good chocolate having them over here. Yes, just to be more precise about Chuck's excursion there,

darker skin people absorb more sunlight than lighter skin people. And it's your albedo. It's the percentage of incident energy that you absorb relative to what you reflect. Very important calculation for the Earth because what Earth absorbed drives our climate, whereas what Earth reflects back to space just goes back to space from the sun.

And so glaciers reflect light, cloud tops reflect light, oceans reflect light, that sort of thing. So for climate change to solve it, we just need to get a bunch of white people in one place. Just reflect the light to reduce the... Do us a favor, guys. Sunbathe. Everybody just sunbathe right here. Reflect out the sun. Okay. All right. I'm sorry. I had to do it, man. All right. Don't write. Don't write.

But it was good. That was funny. That was a good one. Yeah. I mean, if you, if the earth is getting hot, you just, just increase its albedo to increase the reflectance of it. Right. Yeah. So instead of Chuck's solution, everyone could just wear white clothing. And that would show even better. That's more inclusive. I'll give it. That's more inclusive. the DEI authorities will tell you that's how you do that on the campus so so here's a thing if I made you tinyer and tinier and tinier right so you're no longer a macroscopic human you're a microscopic particle there's a particle size below which when you open the curtains and shined light on you that light will hit you and pop you into another location so I'm

smaller than the photon than what the your your capacity to move to a different state of existence that the energy that is required to make that happen correct got it's energy the same as the energy of the light that's hitting you gotcha so you hit me with in order to see in order to see you right and then you pop somewhere else and i say where'd you go right so what are you doing so am i there am i not there. Well, we'll never really know because you're hitting me with something that makes me not there once you're exposing me to it. Correct. And since it happens on the moment you're exposed, not the moment I see you, I will never know what you were doing. Exactly. Okay. If you're small enough for that light energy to, to affect you in that way. So that's why we don't think about

this in everyday life, because we're too big for light to pop us into other states of existence. But particles, electrons, atoms, all of this, it happens all the time. And this was a very disturbing discovery in the 1920s. We're in the centennial decade of the discovery of quantum physics in the 1920s. Because you discover this, I want to see what you're doing. Oh, my gosh, you're not going to let me see what you're doing. Because the light I shine on you in order to see it is. So it's really, it's not so much an observer effect.

It's a measurement effect. Exactly. Okay, get the human brain out. It's just a device to measure you, you can't know it. Okay. Right. So, so let's get on to, so it has nothing to do with consciousness. So let's get on to Schrodinger's cat.

By the way, it's from an error where people spoke lightly of doing bad things to cats, okay? Oh, no, Peter. So, you know, yeah, Peter wasn't around. So, so I'm a little disturbed that they picked cats, right? They could have picked dogs. They could have picked worms, but cats are lovable and will fit in a box, right? Right? And so because house cats don't come as large as house dogs do. Just think that through. Right. Can you imagine? Yeah, a box for a dog is called your living room.

Right. Right. So here's what happens. You say to yourself, you put a cat in a box. And if the cat is a quantum cat with two states, states of existence, it's either dead or a. alive. While it's in the box, you have no idea which it is. And so the way we describe this in quantum physics, if you do the experiments, okay, so some percentage of the time, you open the box, the cat will be alive. Others, the cat will be dead. And so you, what we say is that the cat's existence is a superposition of being dead and being alive. I got you. It's a superposition of those two states. Because it's in the box. It's in the box and you're not looking at it. And you're not looking at it. And that's why their superposition exists. Correct. And it's a quantum cat, not a macroscopic. It's not, it's not, it's not Maru, the internet cat that people love to

see jump out of a box. Okay. All right. It's a hypothetical quantum cat. By the way, do you know cats on the internet took a steep rise the same year that cats on Broadway closed? the musical? Really? Yes. Check your data on that. That is a weird little fact tool. So we need somebody to investigate that because where did those cats go is what.

So it was like 1990, you know, early internet, you know, and cats closes on Broadway. And so I think people needed their cat fix and it landed on the internet. But anyhow, so here we go. Now the silver position. The details of that experiment are more intricate than what I'm describing to you. Because what they wanted was to have like a something that's radioactive that would decay, and then that would then trigger a gate that would open the box. You know, it's a little more Rube Goldbergian than what I'm describing.

But just to be clear, if you don't look in the box, you do not know if the cat is alive or dead. So the Schrodinger's cat is you're talking about something that you don't know about until you actually investigate it. It's the end of the movie seven. I didn't see that. That was a movie that came out many years ago with Morgan Freeman and the beautiful man. I forget his name. Oh, God, he's, he did 12 monkeys.

He's done Thelman Louise. What's his name? Brad Pitt. Thank you. Oh, Brad Pitt, of course. Brad Pitt. So Brad Pitt is stalking a serial killer who is looking, who is using the seven deadly sins to kill people. Long story short.

The last murder. he puts the head of someone in the box and Brad Pitt wants to know it's in the box and Morgan Freeman says don't look in the box there's no reason for you to look in this box and Brad Pitt goes

what's in the box because he knows that it's his wife's head that is completely morbid like what I know but it's perfect it should be called Struthander's cat It's going to be called Brad Piff's White's head. Chuck, that is the most morbid analogy to this example I have ever heard. Oh, oh, because a dead cat is perfectly fine.

Oh, no, okay. So this actually, in a way, applies to quantum computing, which you might have heard snippets about, or at least bits of headlines that are making the news. So if we think of regular computing is like a zeros and ones, bits, right? And all calculations are done. in this way. Well, quantum computing, a bit, a quantum bit, otherwise known as a qubit, can be either a zero or a one or anything in between. Okay. It could be 80% one, 20% zero,

50, 50, 50, 80%, 0, 20% 1, or anything on that continuum. And so, so the qubit has more computational versatility than a regular bit that can only be either a zero or a one. And when I say you can be anywhere between a zero or one, statistically, you can have that bit represent 80% ones, 20% zeros, 50%, it can be any combination of those two in the service of the programming that you're introducing to the computer. So all of that, Schrodinger's cat, your, uh, dead wife's head in a box from this morbid movie that now I'm never going to see. You were so excited about it, too.

Because it's so much better than Stranger's cat. It actually represents something that is consequential that, you know, I mean, never mind. It doesn't really make a difference. I mean, it doesn't make any difference once you're in the quantum. It doesn't make a difference. but it's just a much cooler reference. Right, right, because it's not a quantum head. It's not a quantum head, so it doesn't make a difference.

You know, once you're in a quantum, it's not a cat. It's a quantum cat, and it's not a head. It's a quantum head. So, you know. I see what you're saying. It was never really a cat to begin with. Right. It was a fictional quantum cat.

And the same way, it's a quantum head. Exactly. Exactly. The world according to Chuck. Yeah. That's so funny. You're like, Chuck, go have another bowl and get back to me. So Chuck, there it is.

That's like, you know, Schrodinger's cat 101. He could have called it Schrodinger's coin. Is it heads or tails? Right, right. Exactly. It's just, is the quantum state only have two possibilities in that description? And so once you open the box and thereby gain access to information that is otherwise hidden from any observer or any. device that would make

the measurement. Coin is actually the best representation since if it's a superposition like we said, or like you said, like I said, right? Please. Look at me taking credit for quantum discoveries.

However, that means it's always a probability. It'll be a probability, correct. It's always a probability. So that means quantum coin is actually, you came up with the best one. Why do you got to do that? Why you got a best me on I come up with a head in the box and then you still got it you still got to outdo me really we can't leave we can't leave our fans with a head in a box version of this I'm sorry

and just to be clear the the quantum state doesn't have to be one or the other right it depends on the atom and the circumstances but it can be any number of different states that each have a probability of being true exactly and in fact the way function of the particle extends outside of the box. Oh. So the probability drops rapidly across the border of the box,

but it still exists in a little bit outside the box. So what's inside the box has a probability of spontaneously disappearing from inside the box and appearing outside the box that's called tunneling, and it does that instantaneously,

like faster than the speed of light. Another spooky freaky thing in quantum physics and that relates in part to quantum entanglement because you can have two different particles whose wave functions interact on a way that where you do something that one particle the other one knows about it instantly because their wave functions communicate this is quantum 101 is like fun parts of quantum that is a lot of fun we should do a lot of these about quantum physics this was like an overview i can spend a whole explainer on each one of these things because this is the decade in the 1920s was a watershed decade in physics where Hubble discovers that we that the

Milky Way is not the only galaxy there are other island universes they were called um in indromeda is another galaxy containing 400 billion stars and four years three years later in two in 1929 he discovered that the universe is expanding and we apply Einstein's relativity to show that we've got possibly a big bang, which would later make 50 years before we had the supporting data. And most of what we now know, understand, and love about quantum physics was discovered in the 1920s. And we knew all of that before the neutron was discovered. And before Texas interest meant actually made a calculator.

Uh, yeah. And why is that? Because that means these guys had to work that math out on their own. Okay, before anybody made a calculator. Right, right, exactly. Exactly. By the way, I had a friend who had the very first Texas Instrument scientific calculator. And you knew it was the first because it didn't even have a model number on it.

Wow. It predated model. It would ultimately become the TI 35. But I remember we all crowded around it, staring at it. It was one of those moments that you never first. forget. Okay, I just love the visual of a bunch of nerds crowded around and then, you know, you think they're looking at a magazine or something. And then you part the ways and they're all around a calculator. Like, oh, look at that. Can you believe this thing? Welcome to the geek universe.

Do the cosign. Do the cosine again. I'm a tangent man myself. So if you're standing on one side of the other side of the hill. So if you're standing on one side of a hill. Okay. And you've got to get to the other side of the hill. you're going to climb over the top of the hill and come down the other side. Yeah, or, I mean, that's why I had children. They're going to pull me up over the hill.

Let them call your ass. Let them do the work, lazy. I'm going to sit right here in this little cart. Y'all get moving. So another way to do it is to bore a hole through the mountain, through the hill, and come out the other side. So true. By doing so, you've made a tunnel. Correct.

Okay. So you've made it easy. to get from one side of the hill to the other, because you don't have to go up and then come back down. As a person who lives in Jersey, I appreciate that concept. The tunneling from out of Manhattan. That's correct. Correct.

Okay. So, here's something interesting. In quantum physics, we can think of the hill as an energy barrier to you. Okay. Okay. That makes sense. All right. So you need energy to ascend the hill.

Otherwise, you'll just stay where you are. So now we check how much energy do you have? Oh, I can get halfway up the hill, but not any further. Three quarters of the way, but not any further. Okay? So in quantum physics, if there's a hill, we call them potential barriers, because, all right, they're actual barriers, but they're called potential barriers. So there it is.

And you have a particle on one side of that barrier. and you give the particle energy that can't make it, I can't make it. This hill is too much. Why you got to, let's just stay here. Why don't we just live here now? You wiping the sweat off your brow like electron sweat. You have no idea how hot that nucleus.

So, so what I have, so what I have, so. The particle, however, is not only a particle, it's also a wave. Okay. And when you're a wave, there's something called a wave function. And a wave function is the probability of finding it anywhere in a volume span by that wave function. Okay? So you're more likely to find it where the wave peaks and where the wave drops off, you're less and less likely to find it there. And there's a point where it don't ever wait around because it won't show up for trillions of years.

All right. So, but there's an actual. likelihood, it can show up anywhere in the wave function, even in the low probability places. All right. So that wave doesn't know about and doesn't care about the mountain. Okay. So you can ask, does some of that wave show up on the other side of the mountain? Uh-huh.

If it does, then there is a probability that the particle that's stuck on one side will simply appear on the other side of the mountain having never had to ascend it in the first place because it didn't have enough energy to do it but because it exists as a wave function there will always be a probability that it can show up where it was not invited oh that's called quantum mechanical tunneling quantum wedding crashing that's it we built this wall You're supposed to stay out. Did you see that potential barrier? Did you see that wall?

Does the potential barriers mean anything to you? This would be good for Trump. They built the wall. To keep you out. But they're still tunneling in. There must be quantum mechanical entities. This is the thing. Why aren't these...

Why aren't these quantum... From Norway. I'm sorry. Why can't we get to what's from Norway? They wouldn't have to tunnel. Okay. So that's just quantum tunneling. So I'll show you how that manifests.

Very interesting little history here. And then we'll call it quits because this is just an explainer. In the early days, 100 some years ago, we didn't know where you got all the elements in the universe. Okay. Okay. By the way, I remembered asking my high school chemistry teacher, where do the elements come from? Oh, they're in the earth. And I would later learn, no, we made these suckers and stars, dude. All right. Won't you look up every now and then? Oh, that is so funny. Okay. So it's not his fault. He's a chemistry teacher. He thinks of the elements.

And we know how stupid they are. No. Come on. To be honest. He's a chemistry teacher. He's no physicist. Come on. What do you want? Chuck. What are you want? So, so. So. So in the early days, the question was, where do we get these elements from? You could build them from smaller elements, all right? If you merge them, so they did the calculation of what it would take to merge two hydrogen atoms. Okay?

Now, what's in the nucleus of a hydrogen atom? A proton. So you have a proton here and a proton there, and I want to merge them to make a nucleus that has two protons in it, which would be helium. that's a way to build elements from scratch okay so a proton is what charge uh wait the proton is positive positive and the charge on the other proton it's also positive it's also positive like charges oh they don't really like each other they repel okay so you have to get them close enough so that the a strong nuclear force kicks in and

holds them together. Okay? That's the basic task you have to accomplish here. Sounds like Thanksgiving dinner at my crib. To force it in.

Right. Get in there. Get in there. Right. So it turns out the electromagnetic repulsion, the two positive charges, you can sort of get them

closer and closer if you speed them up by increasing the temperature of the plasma. They'll speed up, they'll get closer and closer and closer to each other.

as you increase the temperature. So you ask, at what temperature will they be close enough for the strong nuclear force to kick in and grab them? Okay, that's the question. Okay, that's the question.

Okay, that temperature is like a billion degrees. Well, there you have it. A billion, and we look, and we do the calculation for the centers of stars, it's not a billion degrees. So I'm taking it that the building of the elements

doesn't work by getting a billion degrees. No, it would, if you could. If you could, but I'm saying, Yeah. Right, right. So the question was, so I think it was Eddington, a famous physicist of the day, astrophysicist, he was asked, he said, well, then where are we going to get the elements? He says, I don't know where, but if it's going to happen anywhere, it's going to be in the center of stars.

Okay. So even though we couldn't give him a billion degrees, he still said, I don't see any place else in the universe that will satisfy the needs of this requirement, except the centers of stars. Okay. So there it just sat for decades. Okay, not many decades, but we sat there as an unsolved problem until quantum physics came along. And then they said, okay, here's a proton coming close to another proton, so there's a barrier there that it can't cross. But wait a minute, the particles are also waves, and part of that wave exists within the grasp of the strong nuclear force. Right.

And so there's a probability that some of these particles will merge and make helium. Wow. So then you say, what is that probability? So, so they said, well, what is the temperature, the center of the star? They said 10 million degrees. There's not a billion. It's like 10, 15 million. So you do the math on the quantum physics and you say, what percentage of collisions

will tunnel through this barrier and end up making? making helium, you come up with that percent, and ba-da-bing, you recreate the total energy output of the sun. Look at that. So you're glad it's not converting every encounter into energy. Right. The sun would just blow its smithereens. Well, yeah, yes, just like, why is everything, God, damn is hot?

Says the person who by then is just a person who by then is just, Just a puff of smoke. Exactly. You don't have time to utter those words. Right. Wow. Okay. That...

Fascinating. So... So the thermonuclear fusion in stars that generates the energy at the temperatures it does can only happen because of quantum mechanical tunnel. That's... Boom. That is amazing! And so just think about the challenges the, you know, we astrophysicists have.

We have. By the way, so Eddington was right. It does happen in the centers of stars. Of course. Right? Because nowhere else was rational, right? But we didn't know enough physics at the time it was proposed to answer that question. New physics had to be invented. And this is why we are always so excited when new physics comes along. There are people saying, people say, oh, someone has a new physics idea, but everyone else is rejecting it because they don't want to lose their highly invested lives in this, in this, they're thinking that we don't like new ideas.

They got to you, Neil. We love new ideas because they give a whole new understanding on the frontier of stuff that we didn't previously understand. Right. And so, yeah, that's quantum mechanical tunneling. Oh, one other thing, it, no matter the size of that potential barrier. Right. It tunnels and appears on the other side instantly.

Oh, so, okay, so, okay. The wave function just collapses and it's there. Right, right. It doesn't travel there. It was always there, probabilistically, okay? So when your wave becomes the particle, boom, it is there. So then distance makes no, it's immaterial. It's immaterial.

It's instantaneous. So we think that it moved, but it really didn't. It was always there to begin with. That is so freaky. It's freaky. That is so freaky. All of quantum physics is, that's only part of the freaky stuff. Yeah.

That's like the 12th, the freakiest thing I could tell you. Yeah. Because you can't handle the other 11th. I can't handle this. You can't handle it, too. Oh, there's another one. We'll save it for another one. Talk about a Bose-Einstein condensate.

The Bose-Einstein condensate. Yeah, let's save that for another explainer. Yeah, okay, cool. That's a good one. Yeah. That's a totally good one. That sounds delicious, like something like. You know, right.

Tonight's special is a farm raise, Bose, Einstein condensate with an arugula compost that we have distilled down into a deconstructed quantum. My boy's been to some restaurants late, get that fancy restaurant vocabulary going. That's pretty wild. The Bose Einstein condensate. We'll get to that. We'll get that.

It relates to this, in a little bit. A little bit relates to, not really, but it's another freaky, wacky, quantum phenomenon that we'll say it will say for another time. We got it. All right, Chuck, another explainer. Great. Quantum tunneling, baby.

Be there. All right. Neil deGrasse Tyson here with Chuck Nice. Four star talk. Keep looking at. Come on.